Constraining the top quark effective field theory using the top quark pair production in association with a jet at future lepton colliders

Abstract: Our main aim in this paper is to constrain the effective field theory describing the top quark couplings through the $e^{-} e^{+} \rightarrow t \bar{t}+$jet process. The analysis is carried out considering two different center-of-mass energies of 500 and 3000 GeV including a realistic simulation of the detector response and the main sources of background processes. The expected limits at 95\% CL are derived on the new physics couplings such as $t \bar t \gamma$, $t \bar t Z$, and $t \bar t g$ for each benchmark scenario using the dileptonic $t \bar{t}$ final state. We show that the 95\% CL limits on dimensionless Wilson coefficients $\bar{c}_i$ considered in this analysis could be probed down to $10^{-4}$.